Most of our media consumption is streamed through our Apple TV. With almost all of it taking place after our 18 month-old daughter has gone to bed, we often have the volume turned down on our TV pretty far so as not to wake her up. I’ve long wished for subtitle support for those poorly audio-mixed films, and only recently discovered it.
I don’t know which apps this works with, but to activate subtitles in Netflix, all you need to do is hold down the Select/Play button while the movie is playing. This pops up a menu where you can choose for which language to activate subtitles. Handy!
I don’t know when this was added, and perhaps it’s always been there, but I’ve never noticed it until recently and have never come across any documentation of it.